Internal combustion engine



L. M. WOOLSON 1,903,413

INTERNAL COMBUSTION ENGINE April 4, 1933.

Original Filed April 5, 1930 2 Sheets-Sheet 1 Jwomkw L/ONEL M lv'ooLsoAg Zuzana;

8) HI: EXEcUTR/X Ap 1933- M. WOOLSON 1,903,413

INTERNAL COMBUSTION ENGINE? Origifial Filed April 3, 1950 2 Sheets-Sheet 2 Jwwntoc L/ONEL M k/aacaom ucuue BY HIS, EXECUTE/X Patented Apr. 4, 1933 UNITED STATES PATENT OFFICE LIoNEL M.,WOOLSON, DECEASED, LATE or DETROIT, MICHIGAN, BY- EMMA IF. wooLsoN, EXECUTRIX, or BLOOMFIELD VILLAGE, MICHIGAN, ASSIGNOR To PACKARD MOTOR CAR COMPANY, or DETROIT, MICHIGAN, A CORPORATION or MICHIGAN INTERNAL COMBUSTION ENGINE Original application filed Apri1 3, 1930, Serial No. 441,390. Divided and this application filed February 14,

4 1931. Serial No. 515,801.

This invention relates to internal combustion engines and more particularly to lubricating systems therefor, and is a. division ofan application Serial No. 441,390, filed April 3, 1930.

One of the objects of the invention is to provide a lubricating system for internal combustion engines in which the oil is efficiently maintained below a predetermined temperature under all conditions without increasing the rate of oil flow in the system or the size of the cooler.

Another object of the invention is to provide a lubricating system for internal combustion engines in which oil is continuously circulated to a plurality of points in a predetermined cycle during operation of the engine, the essential engine elements being utilized substantially throughout the interior of the engine casing as the distributing circuit.

A further object of the invention is to provide a method of circulating and cooling oil in a closed circuit between engine bearings and a reservoir so that the oil will be maintained at an efficient temperature condition under all conditions without an increase in speed of circulation or size of cooler when the temperature is high.

These and other objects of the invention will appear from. the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a vertical medial section of a radial type of engine showing a lubricatin system-associated therewith in a manner embodying the invention;

Fig. 2 is a partial sectional view of a pump mechanism utilized in the system Fig. 3 is a diagrammatic view illustrating the lubricant circulating system.

Referring now to the drawings by characters of reference, 10 represents a unitary barrel type of easing the open end of which is substantially closed by a removable rear wall 11, the central portion of such wall being open for the accommodation of an inertia starter (not shown) which is preferably bolted thereto so that such opening is normally covered. A plurality of radially disposed cylinders 12 extend through the front end of the peripheral wall of the easing 10 and are provided with flanges 13 which bear against such wall and are secured thereto by a pairofcompression rings or bands It. The cylinders are each preferably formed with an integral head 15 and upon each of such heads is bolted an auxiliary head 16,

In order to permit the'pistons 17 to draw in air charges during their suction strokes each cylinder is provided with a single passage 18 which extends through the integral head 15 and auxiliary head 16, and there is also utilized such passages as the exhaust outlet. A valve 19 is associated with the inner end of each of such passages, it being proposed to keep the valves closed during the compression and power strokes of the "pistons and open during the air intake and the exhaust strokes of the pistons.

The engine illustrated is preferably of the compression-ignition or Diesel type which is of such light weight that it can be utilized to propel an airship, its weight being less than two and ahalf pounds per h. p., developed, With this type of engine, therefore,

it is proposed to inject liquid fuel charges into the air charges while being compressed within the cylinders, and associated with 'each cylinder is a nozzle 21 having a pump mechanism indicated generally at 22 associated therewith, the nozzles extending through the cylinder walls so that the fuel can be forced'by the pumps directly into the interior of the cylinders. The valves 19 are each mechanically actuated by the conventional rock lever, there being a push rod 24 parallel with each cylinder for actuating each rock lever and a push rod 25 associated with each pump mechanism arranged in a parallel relation with the valve push rod of each same cylinder.

The space formed by the casing 10 and the rear cover wall 11 is divided interiorly by a casing reinforcing diaphragm 26 which is detachably secured to bosses projecting from the peripheral wall of the casing section 10, and this diaphragm wall is arranged subband 14. It will thus be seenthat the diaphragm 26 divides the interior of .the crank case into two-compartments 27 and 28, the connecting rod assembly being arranged within the compartment 27, and mechanisms for actuating the push rods 24 and 25 are arranged within the compartment 28 and dr ven from the crank shaft. The crank shaft lllustratcd is of the single throw type and is arranged to extend axially of the crank case, the forward bearing portion 29 of the crank shaft being supported by a ball bearing 30 at its forward end and by a roller bearing 31 at its inner end, such bearings being-carried by theforward hub portion 32 of the crank case section 10. The rear bearing section 33 of the crank shaft is detachably clamped to the crank pin 34 by the bolt 35 and there are crank cheeks 36 to which counterweights 37 are pivotally attached,

A connecting rod assembly is carried by the crank shaft pin 34 and includes a master rod 38 which is formed with a hub 39 through which the crank shaft pin extends, there being a two-part spaced bushing 40 between the hub and the crank shaft pin. Arranged in a circular relation around the hub 39 and carried thereby are a plurality of pins 41 upon which the connecting rods 42 are pivotally mounted. It will be understood that the master rod and connecting rods extend to and are pivotally associated with piston pins 43.

As heretofore stated, the compartment 28 houses the driving mechanism for the push rods which actuate the Valves and the pump mechanisms, such push rods 24 and 25 projecting into the compartment. A ring member 44 encircling the crank shaft portion 33 within the compartment 28, maintains the races of the roller bearing 45 in axial relation with the diaphragm and crank shaft, serves as a mounting for the hub 46 of the cam member 47 and provides a circular recess 48, the purpose of which will be hereinafter described. This .ring member 44 is held axially by the retaining member 49 which is mount: ed in a groove in a crank shaft extension 50. The extension 50 is keyed to the crank. shaft portion 33 and is secured axially by a hollow pin 51, such crank shaft extension having jaws 52 at the rear end thereof for engagement with a starter. The crank shaft extension is formed with a gear 53 which meshes with a gear structure 54 which has a shaft portion 55 supported by a bearing 56 carried by the end wall 11 of the casing. The gear structure 54 is formed with two gears of different diameters, one of ,which meshes with the gear 53 and the other'of which meshes with the internal teeth 57 formed on thecam member 47, such geared connection between the cam and the crank shaft rotating the cam at one-eighth crank shaft speedduring engine operation. A.

The forward peripheral portion of the cam structure is formed with spaced lobes 58 while the rear peripheral portion is provided with spaced lobes 59. The lobes 58 are arranged in aplane with the fuel plunger push rod operating mechanisms while the.

rods 24 and 25, such shaft members being.

pressed into openings in the diaphragm 26 and supported at their opposite ends in bearings 61 formed in the end wall 11. Pivotally mounted upon each of such shafts are a pair of rock levers 62 and 63, the rock levers 62 each engagin a-rod 64 associated with a push rod 25 for moving the same in' an injection stroke when actuated by the lobes 58, while the rock levers 63 each engage with a rod 65 for actuating the valve push rods 24 in a direction to open the Valves when actuated by the lobes 59. It will be understood that the fuel injection operating mechanism is arranged so that it can be adjusted to varythe quantity of charges injected. A conventional form of breather 66 is associated with the upper portion of the casingwall 11, thus establishing communication between the compartment 28and atmosphere. I

There will now be described an embodiment of the invention associated with an engine of the character above set forth. In order to assist in providing a lightweight engine of the character described, it is proposed to utilize some of the elements of the engine proper for conveying lubricating oil in its travel through .the circuits interiorly of the crank case and such an arrangement is made without passages or ducts in the main engine crank case which would serve to weaken the same when sub ected to the explosion and compression loads of a compounds per square inch instead of five hundred pounds per square inch. as in the type of engine illustrated.

The diaphragm 26 is provided with a plurality of passages 67 which extend radially from a circular groove 68 formed in the inner face or hub portion. sages 67, and'preferably'the uppermost, is several times the diameter of the others so that. it has a capacity capable of distributing the quantity of oil which is circulated to theplurality of bearings within the crank case. The hollow rock lever shafts 60, as before One of the pas-- described, are pressed into openings formed in the diaphragm, and a port 68 leads through such fitted ends of the shafts and establishes communication between the interior thereof and the passages 67 in the diaphragm. The uppermost rock lever shaft is formed so that its capacity will be sufficient for conducting lubricant into the associated distributing passage 67, and at the outer end of this uppermost rock lever shaft, there is an apertured plug 69 which is carried within the hollow boss 61 with which the inlet conpassage. In this manner, oil is fed to the bearing 45 and to the bearing surface hubs of the rock levers 62 and 63.

A portion of the oil entering the uppermost of the radial passages 67 passes to the interior of the hollow crank shaft section 33 in a manner which will now be described. The uppermost of the passages 67 communicates with an outlet port 73 with which there 's associated a cap member .7 4 which is secured to the diaphragm by the bolts 75. A ring member 76 encircles the hub of the cam 47 and is provided with an inner circular recess 77, such ring having a hollow boss 78 which communicates with the cap member 74 through a swivel union or conduit 79, such conduit-being mounted in this manner to permit a slight movement of the ring member without disturbing the position of the cap member 74 which otherwise might cause leakage or breakage thereof. The hub 46 is provided with an inner circular groove 80 from which a plurality of ports 81 communicate with the recess 77 in the, ring member, and the oil flows-through the ring member, the cam hub and ports 82 in the member 44, into the recess 48 formed by such member 44 and the hollow crankshaft section 33. A plu rality of ports 83 connect the recess 48 with the interior of the shaft section 33.

It will be seen that the lubricant flows through the outlet port 73 in the diaphragm, through the cap member 74, the conduit 79, the ring member 78, the cam hub and the ring member 44 into the crank shaft. During such travel of the lubricant, the engaging surfaces between the'rot'ated cam and the relatively stationary ring member 78 will be adequately lubricated, and likewise, the bearing surfaces between the cam hub and the relative- 1y stationary ring member 44, as well as the engaging surfaces of the ring member 44 and the crank shaft. Any excess oil passing through suchbearings and through the 1101- low rock lever shaft 60 will eventually drain 0; fall into the bottom of the compartment 2 From the hollow section 3.3 of the crank shaft, lubricating oil is distributedto the engine elements within the compartment 27 which require lubrication. A passage 84 leads to the hollow crank pin 34 and a tube 85 extends through the front crank cheek for conducting oil from the hollow crank pin to the bearing portion of the front counterweight 37, while a tube 86 extends through the rear crank cheek 36 and conducts lubricating oil from-the hollow crank section 33 to the bearing surface of the rear counterweight 37, there being a distributing passage 87 associated with such tubes for conducting lubricant. to the bearing surfaces at each end of the counterweight structures.

As heretofore described, the bearing sections 40 between the crank pin and the master rod hub are spaced, and connected with the circular space therebetween is a port 88 which leads from the hollow crank pin and serves to distribute oil therefrom to the master rod bearing and the connecting rod bearings- A plurality of axially extending grooves 89 are formed in the master rod hub and a pair of radial passages 90 extend from each'of such grooves to the hollow interior of adjacent connecting rod pins 41 and a port 91 leads from each hollow connecting. rod pin to the associated hub of the connecting rods 42. It will be seen that the entire bearing portions of the connecting rod assembly willthus be continuously lubricated from the hollow interior of the crank shaft pin.

Some of the oil forced through the various bearings arranged within the compartment V will also be seen that the oil in suspension within the compartment-27 will serve to lubricate the cylinders 12.

Any oil falling. by gravity to the bottom of the compartment 27 will drain through the outlet opening 94, in the lowermost portion of the diaphragm 26, into the bottom of the compartment 28 which serves as a sump. Thelubricating system of the engine illustrated, isof the well known dry sump type. 'Oil drains from some. of the shafts 60 through ports 111 inthe associated rock levers 62 to lubricate the lobes 58 on the cam structure.

The mouth 96 of the outlet conduit 95 is arranged adjacent the bottom of the sump in a compartment 28, and suction created by a scavenging pump, represented generally at A, serves to draw lubricant from the crank case through the conduits 95 and move it through the conduits 97 and 99 leading respectively to a cooler 98 and from the cooler to a tank or reservoir 100. A pressure pump, illustrated generally atB, is connected with the tank 100 by a conduit 101 and lubricant is moved by the pressure pump through the conduit 70 to the distributing system Within the engine casing. The pumps A and B are mounted in a casing structure hereinafter described, and in the event that there is extion, and when an engine of the character described is used as thepower plan of an aeroplane, it is found that under average high temperature conditions a moderate size cooler is suflicient to maintain the oil below a critical temperature. However, on a hot day, with the engine developing its maximum power for continuous periods, it is found that the oil temperatures with a moderate size cooler are excessive. In an effort to improve this temperature condition without having recourse to an excessively large oil cooler, it was found that in circulating the hot oil through the cooler at various rates with an increase in the rate of oil circulation, the efiiciency of the moderately-sized cooler rose rapidly until a peak was reached. For example, 1n circulating one and one-half gallons of oil per minute through such cooler, the oil temperature was reduced sixty-three degrees whereas, when the rate of circulation was increased to six and nine-tenths gallons per minute, the oil temperature was reduced twenty-nine degrees. Multiplying the flow by the temperature difference gives figures of merit, respectively of 94.5 and 200 indicating that the oil cooler under such conditions is practically twice as eflicient with the high rate of flow.

In the engine illustrated, the lubricating system is preferably arranged" so that approximately two gallons of oil flows through the engine per minute and it is not desirable to increase this flow through the bearings nor is it desirable to increase the capacity of the oil pressure pump B beyond that required for the engine since the scavenging pum must at all times have a twenty-five to fi ty per cent excess capacity over the pressure pump, and if the pressure pump bypasses a considerable amount of oil back through the cooler without going through the scavenging pump, then the large scavenging pump will pump considerable air into the system resulting in forming in the oil tank which is a very undesirable condition. In order to secure advantage of the full efiiciency of the cooler without increasing its size and without raising the rate of oil flow through the engine, there is provided means for circulating a quantity of oil directly from the oil tank through the cooler, preferably utilizing the inlet conduit 101 leading to the pressure pump and the return scavenging conduit 97. A circulating pump C is provided for this purpose and communicates with the inlet conduit 101 by means of a passage 104 and communicates with the return conduit 97 leading fromthe scavenging pump A by means of the passage 105. The pumps A, B and C are preferably of the gear type and are arranged in the casing 108 having partitions 109 and 110 forming separated chambers for the pumps. The pumps are all driven bya shaft 106 through means of a gear 107 which meshes with the gear structure 54, previously described. 1

' It will be seen that the system comprises circulating oil under pressure in a closed circuit from the reservoir or tank to the engine parts to be lubricated, that the draining oil is then collected and moved by suction from the engine and returned by pressure through a cooler to the tank. Further, oil from the tank is moved by pressure directly to oil returning from the engine to increase the volume of oil passing through the cooler, thus utilizing a given cooler surface to maintain the oil at an eflicient temperature when exposed to extreme heat conditions.

.While therehas been herein described in some detail a specific embodiment of my invention, which is deemed to be new and advantageous and may be specifically claimed, it is not desired to have it understood that the invention is limited to the exact details of the construction, as it will be apparent that changes maybe made therein without departing from the spirit or scope of the invention.

What is claimed is 1. In a compression-ignition internal combustion engine, a crank case having a plurality of .bearings therein, a tank, a cooler, means connecting the cooler and the tank, means connecting'the oil'tank with the bearings including a pressure pump, return'means for removing excess oil from the crank case to the cooler, and means for moving a stream of oil from the tank into the return means.

2. In aninternal combustion engine a crank case having a plurality of bearings therein, an oil tank, pressure means for forcing oil from the tank to the bearings in the crank case, means for removing oil from the crank case and returning it to the tank, means for absorbing heat from the oil returning to the tank from the crank case, and means for moving a stream of oil from the tank into the oil stream returning from the engine prior to movement into the cooling zone of its travel.

3. In an internal combustion engine the combination with a crank case and engine bearings therein, of a closed lubricating sys tem for conducting oil to the bearings com prising an oil reservoir, a pressure pump communicatin g with the bearings to be lubricated, a connection between the reservoir and the pressure pump, a suction pump, means establishing communication between the lower portion of the crank case and the suction pump, a cooler, means establishing communication between the suction pump and the cooler, a connection between the cooler and the reservoir, the connections leading to and from the cooler being of a larger capacity than the connection between the reservoir and the bearings in the crankcase, a second pressure pump communicating with the reservoir and means connecting the second pressure pump with the connection between the suction pump and the cooler.

4. In a closed lubricating system for the bearings in the crank case of an internal combustion engine comprising an oil reservoir, a pressure pump in communication with the reservoir, means connecting the pressure pump with the bearings to be lubricated, a suction pump, means establishing a communication between the suction pump and the lower interior of the engine crank case, return means establishing communication between the suction pump and the reservoir including a cooler, and means for increasing the volume of oil passing through the return means.

5. The combination with a circuit lubricat- EMMA F. WOOLSON, Eweewtm'm of the Estate of Lionel M. Woolson,

Deceased.

ing system for engine bearings including a tank with which feeding means and return means are connected, of means shunting a continuous stream of the lubricant in the cir cuit around the engine bearings including a connection between the feeding means and the return means.

6. In an engine, a circuit lubricating system for bearings including a tank from which oil is fed and returned, a cooler in the return portion of the circuit,.and by-pass means connected with the system for shunting a continuous stream of oil from the feeding portion into the return portion,the shunted stream re-entering the system prior to flow through the cooler.

7. In an engine, a circuit lubricating system for bearings including a tank and circulating means for feeding oil from the tank and returning oil to the tank, a cooler in the 

